In a wireless communication network, a base station continuously transmits a notification signal by a downlink channel in order to determine whether a mobile station is located in an area formed by the base station. The mobile station monitors the notification signal transmitted by the base station, and moves from one base station to another (handover), transmits an uplink signal, or receives a call (paging) signal. The base station transmits the notification signal at any time of day and night, so that a downlink signal, such as the notification signal, is transmitted even in a place, such as a midnight business district or a less-populated area, where the number of persons who use mobile stations, such as mobile phones, is small, for example.
Patent Document 1: Japanese Laid-open Patent Publication No. 2012-39295
Patent Document 2: Japanese Laid-open Patent Publication No. 2013-131969
Patent Document 3: Japanese Laid-open Patent Publication No. 2012-54767
Patent Document 4: Japanese National Publication of International Patent Application No. 2009-510835
The base station continues to transmit the notification signal regardless of whether a mobile station that may perform communication is located in the area formed by the base station; therefore, unnecessary power consumption due to the transmission increases and the power may be wasted. In other words, a ratio of the amount of actually-provided services to the power usage is low, and the power is inefficiently used in the base station. However, if the base station suspends the transmission of the notification signal, mobile stations are unable to receive the notification signal; therefore, when a user of a mobile station enters the above described area, the user is unable to receive a desired service. Further, if the base station weakens the transmission power in order to reduce the power consumption, an area where services are available is reduced.